CVE-2026-40179

Prometheus is an open-source monitoring system and time series database. Versions 3.0 through 3.5.1 and 3.6.0 through 3.11.1 have stored cross-site scripting vulnerabilities in multiple components of the Prometheus web UI where metric names and label values are injected into innerHTML without escaping. In both the Mantine UI and old React UI, chart tooltips on the Graph page render metric names containing HTML/JavaScript without sanitization. In the old React UI, the Metric Explorer fuzzy search results use dangerouslySetInnerHTML without escaping, and heatmap cell tooltips interpolate le label values without sanitization. With Prometheus v3.x defaulting to UTF-8 metric and label name validation, characters like <, >, and " are now valid in metric names and labels. An attacker who can inject metrics via a compromised scrape target, remote write, or OTLP receiver endpoint can execute arbitrary JavaScript in the browser of any Prometheus user who views the metric in the Graph UI, potentially enabling configuration exfiltration, data deletion, or Prometheus shutdown depending on enabled flags. This issue has been fixed in versions 3.5.2 and 3.11.2. If developers are unable to immediately update, the following workarounds are recommended: ensure that the remote write receiver (--web.enable-remote-write-receiver) and the OTLP receiver (--web.enable-otlp-receiver) are not exposed to untrusted sources; verify that all scrape targets are trusted and not under attacker control; avoid enabling admin or mutating API endpoints (e.g., --web.enable-admin-api or --web.enable-lifecycle) in environments where untrusted data may be ingested; and refrain from clicking untrusted links, particularly those containing functions such as label_replace, as they may generate poisoned label names and values.

• CWE-79

• https://github.com/prometheus/prometheus/commit/07c6232d159bfb474a077788be184d87adcfac3cPatch
• https://github.com/prometheus/prometheus/pull/18506Issue Tracking, Patch
• https://github.com/prometheus/prometheus/security/advisories/GHSA-vffh-x6r8-xx99Mitigation, Vendor Advisory

Published

Apr 15, 2026

Last Modified

Jun 17, 2026

Status

Analyzed

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2026-40173Dgraph is an open source distributed GraphQL database. Versi…9.4
• CVE-2026-40174Masa CMS is a content management system forked from Mura CMS…7.1
• CVE-2026-40175Axios is a promise based HTTP client for the browser and Nod…4.8
• CVE-2026-40176Composer is a dependency manager for PHP. Versions 1.0 throu…7.8
• CVE-2026-40177ajenti.plugin.core defines all necessary core elements to al…7.5
• CVE-2026-40178ajenti.plugin.core defines all necessary core elements to al…5.9
• CVE-2026-4018TOCTOU Race Condition in specific trace commands of the Trac…6.4
• CVE-2026-40180Quarkus OpenAPI Generator is Quarkus' extensions for generat…7.5
• CVE-2026-40181React Router is a router for React. In versions 7.0.0 throug…6.1
• CVE-2026-40182OpenTelemetry dotnet is a dotnet telemetry framework. From 1…5.9
• CVE-2026-40183ImageMagick is free and open-source software used for editin…5.5
• CVE-2026-40184TREK is a collaborative travel planner. Prior to 2.7.2, TREK…5.3